package com.demo;

import java.util.concurrent.ConcurrentHashMap;

/**
 * <p>
 * <code>ConcurrentHashmapTest</code>
 * </p>
 *
 * @author junbao3
 * TODO
 * @date 2023-06-12 10:01
 * Copyright (C) 2021 IFlyTek. All rights reserved.
 */
public class ConcurrentHashmapTest {
    public static void main(String[] args) {
        ConcurrentHashMap<String,String> concurrentHashMap = new ConcurrentHashMap<>();
        //如果key存在 不做任何操作，也不返回值旧值
        concurrentHashMap.putIfAbsent("123","11");
    }
}
